7-Biopterin is a 7-substituted pterin.1 It is formed by non-enzymatic rearrangement of 4a-hydroxy-tetrahydropterin in the absence of pterin-4a-carbinolamine dehydratase (PCD) in vitro and levels are elevated in the urine of hyperphenylalaninemia patients carrying heterozygous mutations in the PCBD gene encoding PCD.1,2
1.ThÖny, B., Neuheiser, F., Kierat, L., et al.Hyperphenylalaninemia with high levels of 7-biopterin is associated with mutations in the PCBD gene encoding the bifunctional protein pterin-4a-carbinolamine dehydratase and transcriptional coactivator (DCoH)Am. J. Hum. Genet.62(6)1302-1311(1998) 2.Curtius, H.C., Kuster, T., Matasovic, A., et al.Primapterin, anapterin, and 6-oxo-primapterin, three new 7-substituted pterins identified in a patient with hyperphenylalaninemiaBiochem. Biophys. Res. Commun.153(2)715-721(1988)